Glaciomarine Records of East Antarctic Ice-Sheet Dynamics

Funding

DFG (2006-2009), Schwerpunktprogramm Antarktisforschung

Background

The question of ice-sheet stability in Antarctica has attracted palaeoclimatic research during the recent past, because of its potential impact on changes in global sea-level and thermohaline circulation. Apart from the dramatic hypotheses of possible total ice-sheet decay in western Antarctica in the face of present global warming, the knowledge of fluctuations of the voluminous East Antarctic Ice Sheet (EAIS) is crucial for the understanding of the late Quaternary global climate system. The EAIS represents the counterpart of the northern-hemispheric ice sheets, which used to respond very fast and abruptly to shortterm climate pertubations during the last glacial cycle and during the Holocene. This topic is addressed in the scope of a DFG project in the Antarctic Priority Programme.

During expedition ANT-XXIII/9 with RV Polarstern to the southern Indian sector of the Southern Ocean, modern sediments and several sediment cores were recovered on a transect from the Prydz Bay Shelf, MacRobertson Shelf and adjacent continental slope towards  the Enderby Basin and the Kerguelen Plateau. The sediment records are studied to gain insights into palaeo glacial dynamics of the East Antarctic Ice Sheet from a marine perspective by the reconstruction of glaciomarine processes in the past. The study area is bordered by the Lambert Glacier-Amery Ice Shelf system that drains about 20% of the East Antarctic Ice Sheet and is considered to be representative for the behaviour of the whole East Antarctic Ice Sheet. The retrieved sediment cores allow the reconstruction of ice-sheet dynamics at different time scales, comprising high-resolution Holocene records, the time interval of the latest glacial-interglacial cycle during the past 130 kyr, and one long-term record back to the mid-Pliocene. Special emphasis will be focussed on the provenance and dispersal of ice-rafted debris (IRD) and the distibution of contourites in space and time, as indicators of palaeo iceberg drift tracks and AABW activity.

The study is linked to the project of Martin Melles & Bernd Wagner (Cologne University) “Environmental history of the Prydz Bay region during the late Quaternary, reconstructed by a multidisciplinary study of lake, fjord, and continental shelf sediments” (see also preceding project). This application is part of the BIPOMAC programme (Bipolar Climate Machinery), an palaeoclimatic initiative in the scope of the International Polar Year 2007/2008 (IPY).

Outcomes

• Voigt, Ines (2009). Spätquartäre Bodenwasserdynamik im Antarktischen Ozean südöstlich des Kerguelen-Plateaus (Diploma Thesis, University Potsdam/AWI Potsdam). 

• Diekmann et al. (2008). Marine Geology in the Prydz Bay – Kerguelen Plateau Area. In: Hubberten, H.-W. (ed.): The Expedition of the Research Vessel „Polarstern“ to the Antarctic in 2007 (ANT-XXIII/9, Reports on Polar and Marine Research, 583: 37-53.

• Diekmann, B. (2007). Sedimentary patterns in the late Quaternary Southern Ocean, Deep-Sea Research II, 54, 2350-2366.

Selected topic-related Publications

• Grobe, H., Diekmann, B., Hillenbrand, C.-D. (2009). The memory of the Polar Oceans. In: Hempel, G. (Ed.): Biology of Polar Oceans, pp. 37-45.

• Diekmann, B., Fütterer, D K., Grobe, H. (2008). Klimabotschaften aus dem Tiefseeschlamm. In: Fütterer, D.K. & Fahrbach, E. (Eds.):  Polarstern: 25 Jahre Forschung in Arktis und Antarktis, Bielefeld, Delius Klasing, pp. 258-264.

• Diekmann, B., Kuhn, G., Gersonde, R., Mackensen, A. (2004). Middle Eocene to early Miocene environmental changes in the sub-Antarctic Southern Ocean: evidence from biogenic and terrigenous depositional patterns at ODP Site 1090, Global and Planetary Change, 40, 295-313.

• Diekmann, B., Fütterer, D. K., Grobe, H., Hillenbrand, C. D., Kuhn, G., Michels, K., Petschick, R., Pirrung, M.(2003). Terrigenous sediment supply in the polar to temperate South Atlantic: Land-ocean links of environmental changes during the late Quaternary, Wefer, G., Mulitza, S., Ratmeyer, V. (Eds.): The South Atlantic in the Late Quaternary: Reconstruction of Material Budget and Current Systems. , Berlin Heidelberg New York : Springer-Verlag, p. 375-399.

• Kuhn, G., Diekmann, B. (2002). Late Quaternary variability of ocean circulation in the southeastern South Atlantic inferred from the terrigenous sediment record of a drift deposit in the southern Cape Basin (ODP Site 1089), Palaeogeography palaeoclimatology palaeoecology, 182, 287-303.

• Diekmann, B., Kuhn, G. (2002). Sedimentary record of the mid-Pleistocene climate transition in the southeastern South Atlantic (ODP Site 1090), Palaeogeography Palaeoclimatology Palaeoecology, 182(3/4), 241-258.

• Diekmann, B., Kuhn, G., Rachold, V., Abelmann, A., Brathauer, U., Fütterer, D. K., Gersonde, R., Grobe, H. (2000). Terrigenous sediment supply in the Scotia Sea (Southern Ocean): response to Late Quaternary ice dynamics in Patagonia and on the Antarctic Peninsula, Palaeogeography, Palaeoclimatology, Palaeoecology, 162(3/4), 357-387.

• Diekmann, B., Kuhn, G. (1999). Provenance and dispersal of glacial-marine surface sediments in the Weddell Sea and adjoining areas, Antarctica: ice-rafting versus current transport, Marine Geology, 158: 209-231.